Pour one pint of thirty-two degrees hot syrup into a small tin basin, adding sixteen egg-yolks, one vanilla bean and two gills of orgeat syrup; set the basin on the fire and stir continuously until the preparation almost comes to a boil, then take it off and when it has lost its greatest heat, incorporate in with a whip one pound of unsalted butter of the very finest quality procurable, dividing it into small pats.
This is a French butter cream built on a cooked yolk-and-syrup base — the ancestor of what pastry kitchens now call a pâte à bombe buttercream. Everything depends on the temperature at which the butter goes in.
Crème à la Quillet takes its name from the Paris pastry house of Quillet, and is traditionally credited to a pâtissier of that name; the gâteau Quillet — génoise layered with this almond-scented butter cream and piped in white on white — remained a fixture of French pastry shops. Charles Ranhofer, who ran the kitchens at Delmonico's in New York and published The Epicurean in 1894, files it among his "Elementary Methods": not a dessert in itself but a component a professional kitchen would keep on hand, alongside pistachio cream (No. 47) and St. Honoré cream (No. 49). The orgeat is the period detail. Almond syrup, once made with pounded sweet almonds and barley water, was a staple flavouring in nineteenth-century confectionery and did the work that almond extract does now, contributing sugar and body as well as scent.